<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <button id="btn">点击获取</button>
    <script>
      function sendAJAX(url) {
        return new Promise((resolve, reject) => {
          const xhr = new XMLHttpRequest();
          xhr.open('GET', 'http://poetry.apiopen.top/sentences');
          xhr.send();
          xhr.onreadystatechange = function () {
            if (xhr.readyState === 4) {
              if (xhr.status >= 200 && xhr.status < 300) {
                // console.log(xhr.response);
                resolve(xhr.response);
              } else {
                // console.log(xhr.status);
                reject(xhr.status);
              }
            }
          };
        });
      }

      let btn = document.querySelector('#btn');

      btn.addEventListener('click', async function () {
        let ddd = await sendAJAX('http://poetry.apiopen.top/sentences');
        console.log(ddd);
      });
    </script>
  </body>
</html>
